An AISI/SAE 4340-A steel rod with the yield strength of 450 MPa, 2.0 m long will be subjected to a tensile force, must have the minimum weight possible, and must behave elastically for this load. The elastic modulus of steel is 207 GPa. What is the engineering strain of the rod

0.002174

Explanation:

Given that the

Yield strength rho = 450 MPa

Length = 2 m

Elastic modulus E= 207 GPa

According to Hook's law, if the elastic limits is not reached, the elastic modulus is the ratio of elastic strength to the elastic strain ə

E = rho/ə

Make ə the subject of formula

ə = rho/ E

ə = (450 × 10^6) / (207 × 10^9)

ə = 2.174 × 10^-3

Therefore, the engineering strain which depends on engineering stress and elastic modulus is 2.174 × 10^-3

Elastic Strain has no S.I Units.

answer: a

a is the answer